JPH09106801A - Cell for battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unit cell for a battery pack in which short-circuiting caused by a loosened connection bar and current leakage caused by wetting are prevented. SOLUTION: A collector terminal 8 is set upright in an upper plate 11 of a cell jar 10 and a connection bar fastening bolt 7 is fastened to the collector terminal 8 through an intercell connection bar 4 fastened by a terminal fastening unt 6. A terminal protective projected part 9 is set upright surrounding the collector terminal 8 being kept from the terminal at a distance enough to screw the terminal fastening nut 6. The terminal protective projected part 9 is formed into a U-shape by an integral resin molding with the upper plate 11 of the cell jar 10 and surrounds the side face of the collector terminal 8 while leaving a space for extension of the intercell connection bar 4. The height of the protective projected part 9 is made higher than that of a connection bar-fastening bolt (connection bar fastening member) 7, so that even when a connection bar-fastening bolt 7 in one side where one intercell connection bar 4 is fastened comes off and a connection bar-fastening bolt 7 in the other side is loosened, the intercell connection bar 4 rotates while getting over terminal protective projected part 9 and further the bar 4 turns while getting over again a neighboring terminal protective projected part 9 and contacts with a neighboring collector terminal 8 or an intercell connection bar 4 and thus short circuit can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a unit cell for an assembled battery which is connected to each other and used as, for example, a battery for an electric vehicle, and more particularly to a short circuit protection structure thereof.

[0002]

2. Description of the Related Art FIG. 4 shows an arrangement example of a battery pack used as a conventional battery for an electric vehicle. Reference numeral 1 denotes a unit cell (cell), which has an electrode assembly (not shown) housed in a unit cell tank 10 each made of a resin sealed case. Ten unit cells 1 are arranged in a row in the thickness direction so as to be stacked to form a battery group (also referred to as a battery module or a module) 2. Further, a predetermined number of battery groups 2 are arranged so that the above-mentioned cell array directions are parallel to each other to form one high-voltage assembled battery. A pair of current collecting terminals 3 forming a positive electrode and a negative electrode is formed on the upper plate of each single battery tank 10, and the current collecting terminals 3 of the adjacent cells 1 are connected by an inter-cell connection bar 4 to connect between the modules. The connection terminals 5 of the adjacent modules 2 are connected by the connection bar 5. 5a is a + side output cable of the assembled battery, and 5b is a-side output cable (ground cable) of the assembled battery.

FIG. 3 shows an example of a method of connecting the collector terminals 3 of the assembled battery disclosed in Japanese Utility Model Laid-Open No. 58-122364. The collector terminal 3 includes a substrate portion 31 that is in contact with the peripheral edge of the terminal hole 12 that is opened in the upper plate 11 of the unit cell tank 10 and is in close contact with the inner surface of the upper plate 11, and a substrate portion 31 that penetrates the terminal hole 12 and extends from the substrate portion 31. The male screw portion 32 is provided upright and is fastened to the upper plate 11 of the single battery tank 10 by the terminal fastening nut 6. The inter-cell connection bar 4 is placed on the upper part of the male screw part 32, and the connection bar fastening bolt 7 is screwed into the female screw hole (not shown) of the male screw part 32 to collect the inter-cell connection bar 4. Male screw part 3 of terminal 3
2

Numerals 91 and 92 are a pair of stopper pins made of an electric insulating material and provided upright around the current collecting terminal 3 with 180 degrees apart from each other around the current collecting terminal 3. The stopper pins 91 and 92 prevent the connection bar fastening bolt 7 from loosening to rotate the connection bar 4 and contact the adjacent current collecting terminal 3 or the connection bar 4 to cause a short circuit accident.

[0005]

However, for example, an assembled battery housed in the body of an electric vehicle uses a large number of unit cells and therefore has a large number of connection bars, and also has a significantly large vibration. The probability of occurrence of loosening of the bar fastening nut is significantly higher than that of the conventional stationary battery pack. In addition, since the vertical vibration of the vehicle body is large in an electric vehicle, it is possible that the connecting bar rides on the stopper pin and comes into contact with the connecting bar fastening bolt to cause a short circuit.

The present invention has been made in view of the above problems, and it is a first problem to be solved to provide a unit cell for an assembled battery capable of preventing a short circuit accident due to a loose connection bar. In addition, in an electric vehicle, it is not easy to completely waterproof a large assembled battery, and rainwater, especially water containing snow melting material, splashes on the top surface of the unit cell, causing a long gap between the + and − current collecting terminals. It is conceivable that a leakage path may be formed over time, or the current collecting terminal may be oxidized or soiled.

The present invention has been made in view of the above problems, and it is a second problem to be solved to provide a unit cell for an assembled battery capable of suppressing leakage and rusting due to water leakage of the current collecting terminal.
The challenge.

[0008]

[Means for Solving the Problems and Effects Thereof] The first structure of the present invention is to stand upright from the upper plate located near the collector terminal fixed to the upper plate of the rectangular cell. A unit cell for an assembled battery having an electrically insulating terminal protection protrusion, wherein the terminal protection protrusion is formed higher than a connecting body or a fastening member connected to an upper portion of the current collecting terminal. It is a single battery.

According to this structure, since the terminal protection protrusion is formed higher than the connection bar fastening member consisting of the connection bar fastening bolt or the connection bar fastening nut screwed onto the upper portion of the current collecting terminal, a loose connection bar is formed, for example. Even if the connection bar is biased by various vibrations and acceleration forces of the vehicle, the connection bar protects its surrounding terminals unless it rotates while being displaced upward by more than the thickness (vertical direction) of the connection bar fastening member. Since the protrusion cannot be overcome and a short circuit does not occur, it is possible to provide a highly reliable unit cell for an electric vehicle, especially for an electric vehicle.

A second structure of the present invention is further characterized in that, in the first structure, the terminal protection protrusion is formed in a U shape so as to surround a side surface of the current collecting terminal. According to this configuration, even if water containing snow-melting material having electrical conductivity is splashed on the upper surface of the unit cell, much of the surrounding area of the current collecting terminal is U.
Since it is surrounded by the letter-shaped terminal protection protrusions, it is difficult to form a leakage path between the + and-collecting terminals, and it is possible to prevent battery consumption and rusting of the collecting terminal due to leakage. it can.

A third structure of the present invention is the same as the second structure, wherein the upper surface of the upper plate in the terminal protection protrusion is
It is characterized in that it is formed higher than the upper surface of the upper plate outside the terminal protection protrusion. According to this configuration, if the water that has entered the terminal protection protrusions quickly flows out of the terminal protection protrusions, the current collecting terminal will not be in a flooded state for a long period of time, and the battery will be consumed and collected due to electrical leakage. It is possible to further prevent rusting of the electric terminals.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the following examples.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the assembled battery current collecting terminal and its connecting method according to the present invention are applied to an electric vehicle battery will be described below with reference to FIGS. However, FIG. 2 is a schematic diagram. Since the connection form of the assembled battery itself is the same as that shown in FIG. 4, the illustration and description thereof will be omitted. However, the components having the same function as the components shown in FIGS. 3 and 4 are denoted by the same reference numerals.

Reference numeral 1 denotes a unit cell (cell) which is a part of an assembled battery, and has an electrode assembly (not shown) housed in a unit cell tank 10 which is a resin sealed case. On the upper plate of the unit cell tank 10, a current collecting terminal 8 forming a positive electrode or a negative electrode is formed. The collector terminal 8 is the upper plate 11 of the single battery tank 10.
A terminal portion 12 that is in contact with the peripheral edge of the terminal hole 12 that is opened to the inner surface of the upper plate 11 and a screw portion 82 that penetrates the terminal hole 12 and stands from the substrate portion 81. The nut 6 is screwed into the male screw surface 83 formed on the outer periphery of the screw portion 82, and the current collecting terminal 8 is fastened to the upper plate 11 of the single battery tank 10. A female screw hole 84 is formed in the screw portion 82 downward from the upper end surface thereof.

Next, a method of connecting (fastening) the inter-cell connection bar 4 to the current collecting terminal 8 will be described. On the flat upper end surface of the terminal fastening nut 6 (or the screw portion 82), the inter-cell connecting bar 4 which is a copper bus bar is placed, and the hole 4 of the inter-cell connecting bar 4 is formed.
The connection bar fastening bolt 7 is threaded through the female screw hole 84 through 0 to fasten the inter-cell connection bar 4 to the current collecting terminal 8 via the terminal fastening nut 6. 71 is a washer.

Around the collector terminal 8, a terminal protection protrusion 9 is provided upright with a space into which the terminal fastening nut 6 can be screwed. The terminal protection protrusion 9 is an upper plate 11 of the single battery tank 10.
It is formed into a U shape by integral resin molding with, and surrounds the side surface of the collector terminal 8 leaving a space in which the inter-cell connection bar 4 extends. The height of the terminal protection protrusion 9 is formed to be higher than the height of the connection bar fastening bolt (connection bar fastening member) 7, whereby one of the connection bar fastening bolts 7 fastening one inter-cell connection bar 4 comes off. Even if the other connection bar fastening bolt 7 is loosened, the inter-cell connection bar 4 gets over the terminal protection protrusions 9 and makes a large rotation, and further crosses over the adjacent terminal protection protrusions 9 again to make a gap between the adjacent current collecting terminals 8 or cells. The contact with the connection bar 4 and the occurrence of a short circuit are prevented.

Further, the water resistance of the collector terminal 8 is improved. In particular, the upper surface 13 of the upper plate 11 in the terminal protection protrusion 9 is
Since it is formed higher than the upper surface 14 of the upper plate 11 outside the terminal protection protrusion 9, the water that has entered the terminal protection protrusion 9 quickly flows out of the terminal protection protrusion 9 and the current collector terminal 8 is extended for a long period of time. It is possible to further prevent the consumption of the battery and the rusting of the current collecting terminal due to the electric leakage without being in a flooded state.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing the vicinity of a collector terminal 8 of an assembled battery unit cell according to an embodiment.

FIG. 2 is a schematic plan view showing a state of an assembled battery to which the unit cells for assembled battery of the embodiment are connected.

FIG. 3 is a longitudinal sectional view showing the vicinity of a current collecting terminal 8 of a conventional unit cell for assembled battery.

FIG. 4 is a diagram showing a layout and connection state of a conventional assembled battery.

[Explanation of symbols]

 7 is a connection bar fastening bolt (connection bar fastening member), 8 is a current collecting terminal, 9 is a terminal protection protrusion, 10 is a single battery tank, and 11 is an upper plate of the single battery tank 10.

Claims (3)

[Claims] 1. A unit cell for an assembled battery, which has an electrically insulating terminal protection protrusion which is located near a current collecting terminal fixed to an upper plate of a rectangular unit cell tank and stands upright from the upper plate. The unit cell for an assembled battery, wherein the terminal protection protrusion is formed higher than a connecting body or a fastening member connected to an upper portion of the current collecting terminal. 2. The unit cell for an assembled battery according to claim 1, wherein the terminal protection protrusion is formed in a U shape so as to surround a side surface of the collector terminal. 3. The upper surface of the upper plate in the terminal protection protrusion is
The unit cell for an assembled battery according to claim 2, which is formed higher than an upper surface of the upper plate outside the terminal protection protrusion.